Examination of the Measurement Equivalence of the Functional Assessment in Acute Care MCAT (FAMCAT) Mobility Item Bank Using Differential Item Functioning Analyses.

The sample was primarily White hospitalized patients, so the results may not apply to other racial or ethnic groups or to patients who were not hospitalized. The study could not examine item bias by race or ethnicity. Patients were split into batches, and each batch did not receive all 111 items, so item comparisons were limited by the batch design. Stair-climbing items had high local dependencies, which can produce false item bias, and this explanation cannot be ruled out. 50% of the items with item bias involved stair climbing, so the finding may reflect a specific item family rather than broad bias. The hospital stay range was too small to analyze length of stay as a subgroup. This is a measurement study, not a treatment study, so it does not show that using the item bank improves patient outcomes.

No conflict-of-interest statement is provided in the supplied text. The article is listed as supported by NIH extramural research.

Do not read the overall score as proof that every item works the same for every patient. Twenty items showed salient measurement bias, stair-climbing items were harder for older patients or women, and the sample was primarily White hospitalized patients.